A defiant President Recep Tayyip Erdogan on Sunday vowed to fight terror "to the end" as a Kurdish militant group claimed twin attacks that ripped through Istanbul, killing 38 people, mostly police.

The bloodshed, which took place late on Saturday, saw a car bomb exploding outside the home stadium of football giants Besiktas and less than a minute later, a suicide attacker blew himself up by a group of police at a nearby park.

The United States consulate in Istanbul was Wednesday offering only limited services with a scaled-down staffing due to information about a possible security threat, the mission said.

"Due to information about a possible security threat against the U.S. Consulate General in Istanbul, the Consulate will open with limited staff and services" on Wednesday, the mission said in a statement.

A female suspected member of the outlawed Kurdistan Workers' Party (PKK) was killed Friday in Istanbul in a police operation against militants suspected to be planning suicide attacks, reports said.

Counter-terrorism police raided a home in Istanbul's Sancaktepe district after receiving a tip-off that PKK militants had arrived in Turkey's biggest city to carry out suicide attacks, Dogan news agency said.

A Turkish woman was killed and her male partner badly wounded in an apparent double suicide bid on Istanbul's best known shopping street, reports said Saturday.

The woman, Zeren Buke Toku, and her partner, Nazif Tugrul Saglam, sat on a pavement on the bustling Istiklal Avenue, where several other young people were out late Saturday, some drinking and others making music, Dogan news agency reported.